Efficient Light‐Emitting Devices Based on Phosphorescent Polyhedral Oligomeric Silsesquioxane Materials

Abstract

Synthesis, photophysical, and electrochemical characterizations of iridium‐complex anchored polyhedral oligomeric silsesquioxane (POSS) macromolecules are reported. Monochromatic organic light‐emitting devices based on these phosphorescent POSS materials show peak external quantum efficiencies in the range of 5–9%, which can be driven at a voltage less than 10 V for a luminance of 1000 cd m−2. The white‐emitting devices with POSS emitters show an external quantum efficiency of 8%, a power efficiency of 8.1 lm W−1, and Commission International de'lÉclairage coordinates of (0.36, 0.39) at 1000 cd m−2. Encouraging efficiency is achieved in the devices based on hole‐transporting and Ir‐complex moieties dual‐functionalized POSS materials without using host materials, demonstrating that triplet‐dye and carrier‐transporting moieties functionalized POSS material is a viable approach for the development of solution‐processable electrophosphorescent devices.

Oligosiloxane Functionalized with Pendant (1,3‐Bis(9‐carbazolyl)benzene) (mCP) for Solution‐Processed Organic Electronics

“…The photoluminescence (PL) spectrum of displays intense UV emission peaks at 346 and 363 nm. The absorption and emission spectra of ODCzMSi are nearly identical to those previously reported for phenylcarbazole structure and mCP,38, 39, 41–43 suggesting that the oligosiloxane backbone does not significantly influence the photophysical properties of the organic chromophore. The phosphorescence spectrum in a frozen dichloromethane solution at 77 K revealed a well‐structured band in the region of 400–500 nm.…”

Oligosiloxane Functionalized with Pendant (1,3‐Bis(9‐carbazolyl)benzene) (mCP) for Solution‐Processed Organic Electronics

“…The photoluminescence (PL) spectrum of displays intense UV emission peaks at 346 and 363 nm. The absorption and emission spectra of ODCzMSi are nearly identical to those previously reported for phenylcarbazole structure and mCP,38, 39, 41–43 suggesting that the oligosiloxane backbone does not significantly influence the photophysical properties of the organic chromophore. The phosphorescence spectrum in a frozen dichloromethane solution at 77 K revealed a well‐structured band in the region of 400–500 nm.…”

Electroluminescence from printed stellate polyhedral oligomeric silsesquioxanes

“…The resulting POSS-7 species features phosphorescent Ir-emitters attached adjacently to the POSS core. 11 Photoluminescence in a chloroform solution revealed a peak at 519 nm, which is essentially the same as for the parent alkene-tethered Ir complex. Cyclic voltammetry measurements (Autolab type-II) on POSS-7, with an Ag/AgCl reference electrode and a ferrocene/ferrocenium (Fc/Fc + ) couple as an internal standard, reveal a highest occupied molecular orbital (HOMO) level of POSS-7 at À5.17 eV and E 1/2 ox ¼ 0.37 eV.…”

Recent Developments in the Chemistry of Cubic Polyhedral Oligosilsesquioxanes

“…A series of monometalated iridium-POSS complexes has recently been prepared for potential use in lightemitting devices. 401 The complexes are prepared by the hydrosilylation of the suitably functionalized iridium complexes with either T 8 (c-C 5 H 9 ) 7 OSiMe 2 H or T 8 (OSiMe 2 H) 8 and N-allylcarbazole. Light-emitting devices were prepared by blending the iridium complexes with suitable organic polymeric materials.…”

“…Metal complexes containing T 8 POSS cages have been prepared as materials with optical limiting properties (Table , entries 2−4), as nanocomposite materials (Table , entry 16), or as species containing novel chromophores (Table , entries 17 and 18). A series of monometalated iridium-POSS complexes has recently been prepared for potential use in light-emitting devices . The complexes are prepared by the hydrosilylation of the suitably functionalized iridium complexes with either T 8 ( c -C 5 H 9 ) 7 OSiMe 2 H or T 8 (OSiMe 2 H) 8 and N -allylcarbazole.…”

Oligosiloxane Functionalized with Pendant (1,3‐Bis(9‐carbazolyl)benzene) (mCP) for Solution‐Processed Organic Electronics

“…The photoluminescence (PL) spectrum of displays intense UV emission peaks at 346 and 363 nm. The absorption and emission spectra of ODCzMSi are nearly identical to those previously reported for phenylcarbazole structure and mCP,38, 39, 41–43 suggesting that the oligosiloxane backbone does not significantly influence the photophysical properties of the organic chromophore. The phosphorescence spectrum in a frozen dichloromethane solution at 77 K revealed a well‐structured band in the region of 400–500 nm.…”

Electroluminescence from printed stellate polyhedral oligomeric silsesquioxanes

“…The resulting POSS-7 species features phosphorescent Ir-emitters attached adjacently to the POSS core. 11 Photoluminescence in a chloroform solution revealed a peak at 519 nm, which is essentially the same as for the parent alkene-tethered Ir complex. Cyclic voltammetry measurements (Autolab type-II) on POSS-7, with an Ag/AgCl reference electrode and a ferrocene/ferrocenium (Fc/Fc + ) couple as an internal standard, reveal a highest occupied molecular orbital (HOMO) level of POSS-7 at À5.17 eV and E 1/2 ox ¼ 0.37 eV.…”

Recent Developments in the Chemistry of Cubic Polyhedral Oligosilsesquioxanes

“…A series of monometalated iridium-POSS complexes has recently been prepared for potential use in lightemitting devices. 401 The complexes are prepared by the hydrosilylation of the suitably functionalized iridium complexes with either T 8 (c-C 5 H 9 ) 7 OSiMe 2 H or T 8 (OSiMe 2 H) 8 and N-allylcarbazole. Light-emitting devices were prepared by blending the iridium complexes with suitable organic polymeric materials.…”

“…Metal complexes containing T 8 POSS cages have been prepared as materials with optical limiting properties (Table , entries 2−4), as nanocomposite materials (Table , entry 16), or as species containing novel chromophores (Table , entries 17 and 18). A series of monometalated iridium-POSS complexes has recently been prepared for potential use in light-emitting devices . The complexes are prepared by the hydrosilylation of the suitably functionalized iridium complexes with either T 8 ( c -C 5 H 9 ) 7 OSiMe 2 H or T 8 (OSiMe 2 H) 8 and N -allylcarbazole.…”

Oligosiloxane Functionalized with Pendant (1,3‐Bis(9‐carbazolyl)benzene) (mCP) for Solution‐Processed Organic Electronics

“…The photoluminescence (PL) spectrum of displays intense UV emission peaks at 346 and 363 nm. The absorption and emission spectra of ODCzMSi are nearly identical to those previously reported for phenylcarbazole structure and mCP,38, 39, 41–43 suggesting that the oligosiloxane backbone does not significantly influence the photophysical properties of the organic chromophore. The phosphorescence spectrum in a frozen dichloromethane solution at 77 K revealed a well‐structured band in the region of 400–500 nm.…”

Electroluminescence from printed stellate polyhedral oligomeric silsesquioxanes

“…The resulting POSS-7 species features phosphorescent Ir-emitters attached adjacently to the POSS core. 11 Photoluminescence in a chloroform solution revealed a peak at 519 nm, which is essentially the same as for the parent alkene-tethered Ir complex. Cyclic voltammetry measurements (Autolab type-II) on POSS-7, with an Ag/AgCl reference electrode and a ferrocene/ferrocenium (Fc/Fc + ) couple as an internal standard, reveal a highest occupied molecular orbital (HOMO) level of POSS-7 at À5.17 eV and E 1/2 ox ¼ 0.37 eV.…”

Recent Developments in the Chemistry of Cubic Polyhedral Oligosilsesquioxanes

“…A series of monometalated iridium-POSS complexes has recently been prepared for potential use in lightemitting devices. 401 The complexes are prepared by the hydrosilylation of the suitably functionalized iridium complexes with either T 8 (c-C 5 H 9 ) 7 OSiMe 2 H or T 8 (OSiMe 2 H) 8 and N-allylcarbazole. Light-emitting devices were prepared by blending the iridium complexes with suitable organic polymeric materials.…”

“…Metal complexes containing T 8 POSS cages have been prepared as materials with optical limiting properties (Table , entries 2−4), as nanocomposite materials (Table , entry 16), or as species containing novel chromophores (Table , entries 17 and 18). A series of monometalated iridium-POSS complexes has recently been prepared for potential use in light-emitting devices . The complexes are prepared by the hydrosilylation of the suitably functionalized iridium complexes with either T 8 ( c -C 5 H 9 ) 7 OSiMe 2 H or T 8 (OSiMe 2 H) 8 and N -allylcarbazole.…”